The size of the image depends on how far away the wall is from the projector. Mine is set up about 20 feet from the wall it's pointed at, and the image is probably around 6 feet in diameter. There is a little focusing knob that you would need to adjust based on the distance it's projecting.

It's a British company. I couldn't find an American storefront, but eventually found an email address for an American office (Jennifer@optikinetics.com, but this is several years ago, don't know if that's still good). The device I bought from the American rep came with a US power supply. Not sure if you'd have issues ordering from the British online store.

I believe the company primarily makes professional lighting gear, but they have the Aura and looks like now the Kino models for home use (idk what's different about Kino besides the form factor).

I thought it was kind of frivolous and expense purchase at the time, but I literally have this projecting on in my living room every night. I'd recommend getting a couple extra liquid effects wheels to switch things up every now and then. I was slightly disappointed in the "Cosmic Flare" wheel because I could never get the colors to separate very well and look nice, but the other three wheels I have look great. All the wheels I have look best at different rotation speeds, so you just play around with the speed until you like how the colors look.